Wow Daniel, I am sorry. JWs and most other religions do attact people with low self esteem. And those types of personalities do gravitate to the wrong men and institutions. The only thing you can do is be supportive. She must fill the black hole inside her. It will be difficult because accomplishment builds self-esteem, but people aren't encourage to accomplish in the organization.
Many sisters are very bitter towards me. They have done everything right, didn't go to school, pioneered, married, didn't have kids and they are miserable. They see me, who broke ALL the rules, and I live a very satisfying, balanced life. Our service overseer approached my husband and I at a recent meeting. He greeted us; we asked how he was doing...surviving, you know how it is, just surviving. He turned to me and asked how I was doing; I replied,' I'm thriving." He didn't know what to say, so he just walked away.
But, many of the sisters make (or attempt to make ) viscious comments to me. It must be very frustrating for the 'good' girls. Why don't you two take an evening class at a local community college?